Electric lamp and terminal device



May 1942- T. PRICE 2,283,287

ELECTRIC LAMP AND TERMINAL DEVICE Filed Oct. 11, 1940 INVENTOR 70/4 50PRICE WWW ATTORN EY Patented May 19, 1942 2,283,287 ELECTRIC LAMP ANDTERMINAL DEVICE Towson Price, Glen Ridge, N. J., assignor toWestinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., acorporation of Pennsylvania Application October 11, 1940, Serial No.360,735

18 Claims.

This invention relates to incandescent electric lamps, and moreparticularly to such adapted to function as a combined motor vehicleheadlight and parking lamp, or a combined stop and tail li ht,

The principal object of my invention, generally considered, is toprovide an incandescent lamp, preferably of a general typ such asdescribed in the Wright Patent No. 2,148,314, or of the "Mazda SealedBeam type, adapted to perform a dual function, such as a headlight andparking light, or a stop light and tail light.

Another object of my invention is to provide a motor vehicle headlightlamp adapted, when desired, to function as a parking lamp and therebyavoid the necessity of an additional lamp and lens.

A further object of my invention is the provision of a dual functionlamp having at least one major tungsten filament and a minor tungstenfilament, said minor filament being smaller in cross section, and thenatural tendency of such thinner wire to burn out quicker being overcomeby operating it at lower temperature than the major filament.

A still further object of my invention is the provision of a lamp inwhich the envelope has a conductive or metal exhaust tube serving as alead for a minor filament therein.

Another object of my invention is the provision of a lamp in which adumet," or other conductive, lead wire through the glass exhaust tube ofthe bulb thereof, serves as a lead for a minor filament therein.

Other objects and advantages of the invention, relating to theparticular arrangement and construction of the various parts, willbecome apparent as the description proceeds.

Referring to the drawing:

Figure 1 is a fragmentary horizontal sectional view of a lamp of theMazda Sealed Beam type, embodying my invention the filament arrangementtherein being shown in bottom plan.

Figure 2 is a fragmentary sectional view on the line lI-II of Figure 1,in the direction of the arrows.

Figure 3 is a fragmentary elevational view of the lamp looking from theleft, as shown in Figure 1, in combination with a circuit diagram.

Figure 4 is an enlarged fragmentary sectional view on the line IV-IV ofFigure 3, in the direction of the arrows.

Figure 5 is a view similar to Figure 4 but showing a slightmodification.

Figure 6 is a view corresponding to Figure 2,

but showing another embodiment of my invention.

Figure '7 is an enlarged detailed view of one of the leads prior toclamping the ends of filaments thereto.

Figure 8 is a view similar to Figure '7 showing the lead afterassociated filaments have been clamped thereto.

Figure 9 is a fragmentary view corresponding to Figure l, but showinganother modification.

Figure 10 is a fragmentary sectional view on the line IX-IX of Figure 9,in the direction of the arrows.

Figure 11 is a view corresponding to Figure 9, but showing anotherembodiment of my invention.

Figure 12 is a fragmentary view corresponding to Figure 1, but showing afurther embodiment of my invention.

In the well-known Mazda Sealed-Beam lamps for automobile headlights,there are two coiled tungsten filaments; that is, one producing an upperor driving beam, and one producing a lower or passing beam. The firstfilament is of higher power (say about 33%) than the other, but they areboth high powered filaments. The driving beam filament is in focus withrespect to the reflector portion of the bulb or envelopeand the passingbeam filament, is slightly out of focus and adapted to direct lightsomewhat downward and to the right, to thereby avoid blinding drivers ofapproaching vehicles.

It has heretofore been customary to use a separate fixture for theparking or minor light, when using such sealed beam headlights, therebynecessitating the employment of separate lenses and reflectors, as wellas splitting up the streamlining of the fenders, when such parkinglights are fixed therein.

In accordance with my invention, I propose to obviate the use of aseparate lamp by incorporating a parking filament in the bulb with thehigh powered filaments, or as an alternative, as

' when used with only one high powered filament,

in the same bulb with said filament. For example, my invention isadapted for incorporation in a headlight that has only one high-poweredfilament, or stop light in which the minor filament may serve as a taillight in the same bulb with the stop light filament. If used withdriving and passing" filaments operating for efficiency in an inert gasatmosphere at temperatures of about 2630 and 2610 0., my minor filament,which may be about 3 watts rather than, respectively 40 and 30 watts,may be operated at about 2200 C. to thereby insure that it will normallyburn as long as the major filaments to avoid prematurely spoiling thelamp.

Referring to the drawing in detail and first considering the embodimentof my invention illustrated in Figures 1 to 4, inclusive, there is showna lamp I2 of the type commonly designated as a "Mazda Sealed-Beam lamp,adapted to serve as a headlight for a motor vehicle. Said lamp may beconstructed in accordance with the teachings of the Wright Patent, No.2,148,314, except as specifically described, and comprises a dishedglass portion I3, preferably formed of Pyrex," which-is a borosilicateglass the inner or concave surface l4 of which is desirably parabolic,or substantially so, and coated with light reflecting metal I5, such asaluminum, applied in a customary manner, as by vaporization thereon.

Through the glass portion l3 project metal contact terminal devices l6,l1 and I3. The contact terminal devices l6 and I! are termed "simplex byme as they each involve only one lead, and are each desirably of theform conventionally used in such lamps, so only one need be described indetail. The device i6 comprises an iron or steel post member l9, havinga head 2| from which projects a boss 22, and from the other end of whichextends a relatively stiff lead 23 (to which is secured an end of thedriving" or "in-focus filament 24), which may be formed of nickel-platedcopper. The connection is desirably eifected by splitting the end of thelead, as indicated at 25 in Figure 7, and after insertion of thefilament end-portion, forcing the leaves of the split portion together,as indicated at 25' in Figure 7, to thereby hold the filament in place.The corresponding end of the meeting filament 26 is supported from thedevice I! in a similar manner.

To the under surface of the head 2| is secured, as by brazing orwelding, a skirt member 21, preferably formed by Kovar, Fernico, orother material of suitable coeflicient of expansion for sealing into thelamp envelope, having a sharp edge portion connected to the base portionof the lamp l2 by a fused glass seal, said edge portion being desirablyembedded in the glass of the base portion, as indicated at 28. I

In the present embodiment all of the three terminal devices have theirouter bosses fitted in metal ferrules or hollow rivets in a disk 29',formed of Bakelite or other heat-resisting insulating material, andconnected thereto as by means of solder or the like. From said ferrules,extendcontact plates 3|, 32 and 33, for connection with the battery 34of the vehicle through any desired switch 35, as indicated in Fig. 3.

The bulb of the lamp I2 is completed, for exhausting and gas fillingthrough the exhaust tube 33, indicated as tipped off, by fusing the lensor cover glass member 31' thereto in the customary manner, after thefilaments 2425 and the parking filament 31 have been positioned, asshown.

The manner of application of the parking filament in the bulb of thelampwill now be described. The metal contact terminal device I 3, termed"duplex by me as it involves two leads, instead of being of conventionalform, is, as shown in Figure 4, made of a hollow metal post member 38,having a head 39 and a boss 4|, extending from said head and secured tothe ferrule 42 and associated contact plate 33, as by solder or thelike.

As in the case of the other terminal devices,

33, as by welding, and its sharp edge portion embedded in the glass ofthe lamp base, as indicated at 44.

In the present embodiment, the member l3 carries two leads, 4' and 42,insulated from one another in any desired manner, as by coating the lead43 with asbestos, glass, lavite, or other heatresisting insulatingmaterial, where it passes through the member l3, as indicated at 41.

The portion of the leads 4! and 43, where they emerge from the inner endof the member l3, are desirably insulated from one another and held inplace by a glass bead 43, fused to the free edge of the member 33,preferably with the inner end portion of said member embedded therein,as illustrated in Figure 4, and through which the leads 4! and 43 pass,thereby making a vacuumtight seal.

The insulated lead 43 may be adapted for connection with the battery 34,in any desired manner, as by continuing it outwardly and across toconnect with a fourth contact plate 43 held on the Bakelite disk 23 by aferrule 3|, like the other a thin skirt member 43 is secured to the headcontact members 3|, 32 and 33.

The uninsulated lead 45 is connected to the ferrule 42 and associatedcontact plate 32 in any desired manner, as by welding, brazing orsoldering. as indicated at 52.

Figure 5 shows an alternative construction for the third metal contactterminal device which, in this instance, is designated as l3, andcomprises a hollow metal post member 33' having a head 33' and a boss 4|extending from said head and secured to a ferrule 42' and associatedcontact plate 33', as by solder or the like, so as to thereby fasten itto the disk 29', corresponding with the disk 23 of the first embodiment.

As in the case of the other terminal device, a think skirt member 43' issecured to the head 39' with its sharp edge portion embedded in theglass of the lamp base, as in the other forms.

In the present embodiment the metal post member 33' serves as part ofthe return lead, the filament-connected portion of which is designatedby the reference character 45'. The lead 45 is secured to the member 33'in any desired manner, as by welding to the inner portion thereof, asindicated at 58. The lead 46 to the parking filament 31', is insulatedfrom the tubular member 33' and held in place, as by a glass bead 48',fused to the free edge of the member 33', preferably with the inner edgeportion of said member embedded therein, as illustrated, and throughwhich the leads 45' and 46' pass, thereby making a vacuum-tight seal.The head 43' also desirably wets" a portion of the lead 45, spaced fromthe point of connection with the member 33', during the process ofmanufacture, and serves as a brace therefor.

The insulated lead 46' is adapted for connection with the battery 34, inany desired manner, for example, as described in connection with theembodiment illustrated in Figure 4. The uninsulated lead 45' is, ofcourse, electrically connected to the contact plate 33' through thetubular member 38' by virtue of the manner of formation.

The lead 45 is desirably formed to serve as a return conductor for thefilaments 24 and 26, as well as for the parking filament 31, and therebydesirably has a U-shaped branch member 33, secured thereto by welding orthe like, as indicated at 34. The filament 24 has its ends respectivelysecured to the lead 23 and the near arm of branch lead 53, in anydesired manner,

spectively secured to the lead 55 of the device H and the lead 45, andthe parking filament 31 has its ends connected to the other arm of thebranch lead 53 and the lead 46, as illustrated in Figs. 1 and 2.

Reference to Figure 2 will show that while the filament 24 is in focus,the filament 26 is slightly above the focal point thereby giving adepressed beam. The parking filament 31 is also desirably out of focusin the same direction as the filament 26.

Reference to Figure 3 will show that the filaments 24, 26 and 31 may bealternatively energized at will from the battery 34 by moving thethree-way switch member 35 to engage the desired contact H, L or P, asthe case may be, to respectively energize the high beam, low beam, andparking light filaments.

Referring now to the embodiment of my invention illustrated in Figures6, 7 and 8 a construction is there disclosed which is identical withthat of Figures 1 to 4, inclusive, except that the filaments 24 26 aresupported from the leads exactly in accordance with conventionalconstruction, that is, the metal contact terminal devices lfi H and |8correspond respectively with the two lead-in terminals and common orreturn terminal of a conventional Mazda sealed-beam headlight. Thus thedevices l6 and I! respectivel correspond with the devices l6 and ll ofthe preceding embodiment, while the device I8 differs therefrom only inhaving two electrically connected filament supporting leads 59 and 60extending therefrom. The terminal 56 desirably corresponds inconstruction with one of the terminals l6 and H and supports a lead-inconductor 51, to the free end of which is secured one end of a parkingfilament 3'| corresponding with the parking filament 31 of a precedingembodiment. The return lead branch 59 is slit, as shown in Fig. 7, toreceive,

not only one end portion of the meeting-beam filament 26 butalso theadjacent end portion of the parking filament 31 as illustrated in Figs.7 and 8 which respectively show the open and connected positions of thelead ends.

All of these contact terminal devices are secured to an insulating disk29 and have outer terminal plates 3| 32*, 33 and 49 as in the precedingembodiment, except that said contact members are not arranged in thesame order as those designated 3|, 32, 33 and 49.

Referring now to the embodiment of my invention illustrated in Figures 9and 10, there is shown a fragmentary portion of a projector lamp |2 ofthe same type as the previous embodiments, except that the contactterminal devices l6 ll and |8 are of the medium bipost type, forexample, such as shown in the Wright Patent No. 2,098,080, datedNovember 2, 1937.

Said devices I6 and I8 comprise generally cylindrical outer contactterminals 3| 32 and 33 having sealing flanges 6|, 62 and 63 of flaringcup-like conoidal form, whose outer edges are attached to the base orreflector portion of the lamp l2 by glass fusion and embedding therein,around the holes 64, through which the inner extensions 65 of saidterminal In the present embodiment the lamp envelope is shown providedwith a metal exhaust tube 66, which extends'through approximately theaxial portion of the reflector N of the lamp envelope. Said metalexhaust tube may be made of Kovar, Fernico or other material having acoeflicient of expansion sufiiciently close to that of the Pyrex orother glass envelope to seal satisfactorily thereinto.

From the inner end of the metal exhaust tube extends a filamentsupporting conductor 46 and between the free end of said conductor andaportion of the lead-in conductor 53 is a minor or parking filament 31,the ends of which are connected to the respective lead-in conductors inany desired manner, or as disclosed in connection with 'the precedingembodiments.

In order to make it possible to use the tube 66 for exhausting and gasfilling purposes, even though its inner end is plugged by the conductor46, desirably brazed, soldered or welded thereto, a hole 61 is providedin the side thereof.

Except as specifically disclosed in connection with the presentembodiment, the same may correspond with the first embodiment, thetipping-off of the exhaust tube 66 being, however, in accordance withthe difference in material, that is, said exhaust tube must betipped-off by means of a hotter flame than required for melting glass inorder to fuse the end portion thereof into sealing condition, or saidend may be closed by brazing, soldering or welding.

Referring now to the embodiment of my invention illustrated in Figure11, there is shown a construction which is almost identical with that ofFigures 9 and 10, except that the contact terminal devices 3| 32 and 33are of the separated type which have been largely used for Mazda sealedbeam" headlights, that is, they have outstanding plate contact pieces,such as indicated by the reference characters 3|, 32 and 33 inconnection with the first embodiment without, however, using theinsulating plate 29.

In addition to the driving beam filament 24 and the meeting beamfilament 26, I provide a parking filament 31, one end of which isconnected to the return lead branch 45 and the as indicated at 68,.sothat the position of the lead 46 is fixed prior to exhaust. Asupplemental exhaust tube may be taken off from the side of the portion66, or from other suitable location and tipped off at the appropriatetime, leaving a tip designated by the reference character 36. Theprojecting portions 68 and 36 are normally covered by a contact terminalmember 49, which serves not only as a contact terminal for the parkingfilament 31, but also as protection for the tip 6836.

Referring now to the embodiment of my invention illustrated in Figurel2, a construction is there disclosed which is identical with theembodiment of Figures 1 tov 4, inclusive, or that devices e'xtend,making gas and vacuum-tight joints. From the inner ends of saidextensions 65 extend filament supports 23", 55 53 and 45 the last two ofwhich extend from the return contact member I8".

minal device I8 like that designated II in the first embodiment, or l8,except that there is no U-shaped extension corresponding with 53 of thefirst embodiment.

The parking filament 31 extends between the same lead 45, using aconnection such as illustrated in Figure 8, and a lead 46 correspondingwith the lead 46 of Figure 4, or Fig. 5. Such a construction is suitablefor a lamp, either oi the headlight type, where only one major filamentis employed, or of the stop light type, where the major filament mayfurnish the stop light, and the minor filament act as a tail light. Asan alternative, both filaments 24 and 3'! may be high powered filaments,one furnishing the driving and the other the meeting beam.

From the foregoing, it will be seen that I have devised a lamp adaptedto perform dual functions, such as furnish a parking light, as well asmajor beams for driving or as a combination stop and tail light, or as amodification oi the conventional two filaments sealed beam headlight. Ihave also provided a combination metal contact terminal device adaptedto provide two leads through one bulb aperture. Although when used in aheadlight a reflector portion is desirably incorporated as part of thebulb, it will be understood that such a reflector portion may be omittedwhen serving as a stop and tail light.

It will also be understood that I preferably, but not necessarily,employ supporting conductors of smaller gauge, when serving only aminor, parking or tail light filament, than the conductors for the majorfilament or filaments. Any of the several contact terminals may beemployed in connection with any embodiment. This statement also appliesto other features which are obviously interchangeable between thevarious embodiments. I do not wish to be limited, other than by theclaims, to the form of terminal devices disclosed, as electric currentmay be supplied to the filaments by straight-through leads, deviceswithout skirt portions, or other means known for the purpose.

Although preferred embodiments of my invention have been disclosed, itwill be understood that modifications may be made within the spirit andscope of the appended claims.

I claim:

1. An electric lamp comprising a vitreous en- P velope with abase-forming portion shaped and coated with specular metal to provide areflector, metal leads extending through holes in said refiector andsealed thereto, end portions of said leads extending inward into theenvelope to provide filament supports, and outward for connection withfilament-energizing means, a lead of smaller gauge than saidfirst-mentioned leads mounted in said reflector, a major filament withits ends secured to a pair of said metal leads, and a minor filamentsecured to one of said pair and said lead of smaller gauge.

2. An electric lamp comprising a vitreous envelope with a base-formingportion shaped and coated with specular metal to provide a reflector,metal contact terminal devices extending through holes in said reflectorand having thin skirts therearound with their edges sealed to saidreflector by fused glass seals, end portions of said terminal devicesformed as leads extending inward into the envelope to provide filamentsupports and outward for connection with-filamentenergizing means, alead of smaller gauge than said first-mentioned leads mounted in saidrefiector, a major filament with its end secured to a pair of saidfilament supports, and a minor filament, operable at a lower temperaturethan said major filament when equivalent voltage is applied thereto,secured to one of said pair and said lead of smaller gauge.

3. An electric lamp comprising a vitreous envelope with an integralbase-forming portion, metal leads extending. through holes in saidbaseforming portion and sealed thereto, said leads extending inward intothe envelope to provide filament supports and outward for connectionwith filament-energizing means, a lead of smaller gauge also mounted insaid envelope, a major filament with its ends secured to a pair of saidmetal leads, and a minor filament secured to one of said pair and saidlead of smaller gauge.

4. An electric lamp comprising a vitreous envelope with a base-formingportion, metal leads extending through said base-forming portion andsealed thereto, end portions of said leads extending inward into theenvelope to provide filament supports, and outward for connection withfilament-energizing means, a lead of smaller gauge also mounted in saidenvelope, a major filament with its ends secured to a pair of said metalleads, and a minor filament of higher nominal voltage, so that itoperates at a lower temperature than said major filament when the samevoltage is applied thereto, secured to one of said pair and said lead ofsmaller gauge.

5. An electric lamp comprising a vitreous envelope with a base-formingportion, metal contact terminal devices extending through saidbase-forming portion and sealed thereto, end portions of said terminaldevice extending inward into said envelope to provide filament supportsand outward for connection with filamentenergizing means, a wire ofsmaller gauge also mounted in said envelope to provide an additionallead, a driving beam filament mounted on a pair of said supports, ameeting beam filament mounted on another of said supports and a branchof a driving beam filament support, and a minor filament also mounted ona branch of the common support and said lead of smaller gauge.

6. An electric lamp comprising a vitreous envelope with a base-formingportion, metal contact terminal devices extending through saidbase-forming portion and sealed thereto, end portions oi. said terminaldevices extending inward into the envelope to provide filament supportsand outward for connection with filamentenergizing means, some of saidcontact devices being simplex and one duplex, the latter comprising ahollow metal tube, a lead-in conductor extending through said tube andinsulated therefrom, a driving beam filament connected to one of saidsimplex terminal devices and the tube of said duplex device, a meetingbeam filament connected to another simplexdevice and with said tubeforming a common return for both, and a minor filament connected to saidinsulated leadin conductor and tube.

-7. An electric lamp comprising an envelope, a duplex contact terminaldevice comprising a hollow metal tube extending through said envelope,and sealed thereto, a lead-in conductor extending through said tube andinsulated therefrom, a lead-in conductor electrically connected to saidtube, and a filament with its ends respectively connected to saidelectrically connected and insulated conductors.

8. An electric lamp comprising a vitreous envelope with a base-formingportion, metal contact terminal devices extending through saidbaseforming portion and sealed thereto, end portions of said terminaldevices extending inward into said envelope to provide filament supportsand outward for connection with filament-energizing means, one of saidsupports serving as a common return, and a plurality of filaments withtheir ends respectively connected to said supports with a plurality ofsaid ends secured in a single slit in said common support.

9. An electric'lamp comprising a vitreous reflector portion, a metalexhaust tube sealed through said reflector portion, a cover glass unitedto said reflector portion to form a hermetically sealed enclosure, and alight source mounted in said enclosure in definite relation to the focusof said reflector portion, said source comprising a major filament and aminor filament, a pair of leads for said major filament, a leadtelescoping in said exhaust tube and one of said pair serving as theleads for the minor filament.

10. An electric lamp comprising a reflector portion, an exhaust tubeextending therefrom, a cover glass united to said reflector portion toform a hermetically sealed enclosure, and a light source mounted in saidenclosure in definite relation to the focus of said reflector portion,said source comprising a major filament and a minor filament, a pair ofleads for said major filament and another lead extending through saidexhaust tube, sealed thereto, and serving as a lead for the minorfilament.

11. A combination return lead and minor filament contact for an electriclamp, comprising a hollow metal tube having a skirt secured to one endportion thereof, a pair of lead-in conductors extending through saidtube, and means insulat ing said conductors from each other.

12. Acombination return lead and minor filament contact for an electriclamp, comprising a hollow metal tube having a skirt secured to one endportion thereof, a lead-in conductor extending through said tube, andmeans insulating said conductor from said tube.

13. A duplex contact and filament lead device for an electric lamp,comprising a hollow metal tube, a lead-in conductor extending throughsaid tube, means insulating said conductor from said mentioned leadsalso extending through a hole in said reflector, a major filament withits ends secured to a pair of said filament supports, and a minorfilament secured to one of said pair and said lead of smaller gauge.

15. An electric lamp comprising a vitreous envelope, filament supportsin said envelope,

tube, and a lead-in conductor electrically connected to said tube.

14. An electric lamp comprising a vitreous envelope with a base-formingportion shaped and coated with specular metal to provide a reflector,metal contact terminal devices extending through holes in said reflectorand having thin skirts therearound with their edges sealed to saidreflector by fused glass seals, end portions of said terminal devicesformed as leads extending into the envelope to provide filament supportsand outward for connection with filament-energizing means, a lead ofsmaller gauge than said first some of said supports being simplex andone duplex, the latter comprising a metal tube and a lead-in conductorextending through said tube and insulated therefrom, a major filamentelectrically connected to one of said simplex devices and said tube,another major filament electrically connected to another simplex deviceand said tube, and a minor filament electrically connected to saidinsulated lead-in conductor and said tube.

16. An electric lamp comprising a vitreous envelope with a base-formingportion shaped and coated with specular metal to provide a reflector,metal contact terminal devices extending through said reflector andsealed thereto, inner end portions of said terminal devices in saidenvelope providing filament supports, and outer end portions providingfor connection with filamentenergizing means, one of said supportsserving as a common return lead and having a longitudinal groove in oneside, and a plurality of filaments with one set of their endsrespectively connected to said supports and the other set of said endsdisposed in said groove and secured to said common return lead.

1'7. An electric lamp comprising a vitreous envelope with a.base-forming portion shaped and coated with specular metal to provide areflector, metal contact terminal devices extending through holes insaid reflector and having thin skirts therearound with their edgessealed to said reflector by iused glass seals, inner end portions ofsaid terminal devices formed as leads in said envelope to providefilament supports, and outer end portions serving for connection withfilament-energizing means, another lead passing through the same hole asone of said first-mentioned leads, a major filament with its endssecured to a pair of said filament supports, and a minor filament withits ends secured to one or said pair and said other lead.

18. A duplex filament lead device for an electric lamp comprising ametal tube, a lead-in conductor extending through said tube, meansinsulating said conductor from said tube, and means sealing said tubevacuum-tight, comprising a bead of glass in which the inner end of saidtube is embedded and through which the insulated conductor passes, andanother conductor electrically connected to said tube and passingthrough the same bead.

TOWSON PRICE.

